Jay- let us know when you get a chance to check those signal bulbs and/or headlights. I'd be interested to know if they've all burned out (regulator). If not, a bad ground sounds likely.
I just added a second ground wire to the original on my bike- members have said that it'll have more starting power. I noticed that the old lead was pretty dirty at the connection to the motor- wouldn't hurt to clean and scuff that up.
Got horn, tail, and brake lights?